The present invention relates to a clean crosslinkable fluorine-containing elastomer composition containing fine particles of aluminum oxide which can give an elastomer molded article to be used for semi-conductor production apparatuses, for example, a sealing material for sealing thereof, and relates to a molded article which is obtained from the elastomer composition, is excellent in plasma resistance and has the reduced number of micro particles.
In producing semiconductor elements, very high cleanliness is required, and the requirements for high cleanliness range over not only management of a production process of semiconductors but also semiconductor production apparatuses and parts thereof. If the parts of semiconductor production apparatuses are cleaned after built in the apparatuses, a degree of possible cleanliness is limited. Such parts are required to have been cleaned highly before built in the apparatuses. In production of semiconductors, there are various contaminants which come from parts of semiconductor production apparatuses, for example, so-called micro particles which are fine particles generated and released from the parts and impurity gas (outgas) to be mixed into atmosphere gas due to decomposition and deterioration of materials of the parts. Those contaminants have an adverse effect particularly on accurate etching treatment of semiconductor elements.
Also cleanliness is required similarly in a molded article such as a sealing material for semiconductor production apparatuses which the present invention can be particularly suitably applied to. The present applicant has attained high cleanliness of the sealing material itself by employing a special method of cleaning the sealing material after molding (WO99/49997).
The sealing material which is required to have heat resistance and chemical resistance has been produced by crosslinking and molding a crosslinkable fluorine-containing elastomer composition such as a fluorine-containing rubber, and in order to improve mechanical properties such as compression set, there is a case where a metal oxide filler is added to the composition. It is known that as such a filler, titanium oxide, silicon oxide (white carbon), aluminum oxide (alumina), or the like is added (Japanese Patent Publication No. 2783576, U.S. Pat. No. 5,187,222, JP-A-1-118560, JP-A-56-166251, U.S. Pat. No. 4,525,539). In some cases, those fillers are added to enhance whiteness and improve plasma resistance (Japanese Patent Publication No.2858198, JP-A-2000-502122, U.S. Pat. No. 5,696,189).
Also in order to clean the inside of semi-conductor production process, there is a case where a process for cleaning is carried out with fluorine plasma, particularly NF3 plasma. With advance of high integration of semi-conductors, since cleanliness inside the process needs to be maintained highly, cleaning process is repeated many times. In that cleaning process, there is a problem with gasification of the above-mentioned titanium oxide and silicon oxide, namely there is a case where outgas is generated from molded parts made of an elastomer containing such oxides. Also in some cases, micro particles (impurity fine particles) are generated from the molded parts made of an elastomer. Those contamination sources must be eliminated.
Also in a plasma etching process, for etching of a pattern having a high aspect ratio as a result of fabrication of fine structure, and further for enhancing an etching rate, an etching process with a high density plasma has come to be adopted. An etching process with a high density plasma means a plasma process with various gases, for example, under plasma conditions that a plasma density with argon gas is not less than 1.00xc3x971011/cm3 at a pressure of 10 mTorr at an output of 800 W. In such a high density plasma, a fluorine-containing elastomer molded article containing the above-mentioned titanium oxide or silicon oxide is deteriorated remarkably in a plasma process not only with a fluorine plasma such as NF3 but also with oxygen plasma or the like.
An object of the present invention is to provide a fluorine-containing elastomer molded article containing fine particles of aluminum oxide, being excellent in plasma resistance, especially fluorine plasma resistance and being capable of reducing particle generation after irradiation of plasma, and a crosslinkable fluorine-containing elastomer composition to be used therefor.
Further an object of the present invention is to provide a fluorine-containing elastomer molded article containing fine particles of aluminum oxide, being excellent particularly in resistance to high density plasma, and being capable of reducing generation of micro particles after irradiation of plasma, and a crosslinkable fluorine-containing elastomer composition to be used therefor.
Namely the present invention relates to the fluorine-containing elastomer molded article for semi-conductor production apparatuses which is obtained by crosslinking and molding a crosslinkable fluorine-containing elastomer composition comprising a crosslinkable fluorine-containing elastomer component and fine particles of aluminum oxide, wherein an average particle size of the fine particles of aluminum oxide is not more than 0.5 xcexcm, preferably 0.005 to 0.05 xcexcm.
The molded article is suitable as a sealing material to be used for sealing of semi-conductor production apparatuses, particularly for sealing of semi-conductor production apparatuses in which irradiation of high density plasma is carried out.
Also the present invention relates to the crosslinkable fluorine-containing elastomer composition which comprises a crosslinkable fluorine-containing elastomer component and fine particles of aluminum oxide having an average particle size of not more than 0.5 xcexcm and is used for producing the elastomer molded article for semi-conductor production apparatuses.
It is preferable that the crosslinkable fluorine-containing elastomer composition comprises 0.05 to 10 parts by weight (hereinafter referred to as xe2x80x9cpartxe2x80x9d) of an organic peroxide, 0.1 to 10 parts of a crosslinking aid and 1 to 150 parts of the above-mentioned fine particles of aluminum oxide based on 100 parts of the crosslinkable fluorine-containing elastomer, for example, a perfluoro elastomer component.
The present invention also relates to the semi-conductor production apparatuses provided with the above-mentioned elastomer molded article for semi-conductor production apparatuses.